06/07/2026
2299 Scene
35 like it
Short
The European Space Agency’s Euclid space telescope has discovered 31 of the most ancient quasars ever found. Two of these massive and luminous galaxy cores, powered by supermassive black holes, are the oldest quasars ever observed in cosmic history. When the universe was 670 million years old, they shone with the brightness of a trillion suns – only 5% of its current age.
depth in
Artist’s concept of an ancient quasar
Quasars represent a brief stage in the life of a galaxy during which large amounts of material spiral into the central supermassive black hole, releasing enormous amounts of energy. In this stage, the galaxy’s nucleus is brighter than anything in the universe, often hundreds to thousands of times brighter than the rest of its host galaxy.
We’ve been looking for the universe’s very first quasars for decades. These objects reveal what was happening during the early days of the universe, including the first supermassive black holes and how galaxies formed. However, quasars from this time are difficult to find. They are rare, because few galaxies have yet had time to grow large enough, and their primordial light is faint and easy to be confused with stars located closer to us.
Euclid, launching in 2023, is digging deeper into this mysterious part of ancient cosmic history, with exciting results. The telescope has now discovered an unprecedented number of 31 new quasars in the early universe, dating back to the time when the universe was only 5% of its current age.
“These early quasars are in the early stages of the universe,” says Daming Yang of Leiden University in the Netherlands, lead author of the Euclid discovery paper. “By finding and studying them, we can better understand how these giant systems formed and grew so rapidly – one of the greatest mysteries in astrophysics.”
Quasar was discovered by Euclid
below the tip of the iceberg
The earliest quasars we knew about until now were just the tip of the iceberg: the rare and bright outliers that are easiest to identify. We haven’t found enough quasars from the early days of the universe to properly study them as a group. Euclid’s new discovery changed everything, capturing not only the bright outliers but also most of the ancient quasar population.
“Euclid is a true game-changer,” says Deming. “Previously, we could only find a handful of the brightest ancient quasars, but Euclid lets us search more efficiently across vast areas of the sky to capture very little light. It is a unique tool for quasar hunting.”
The discovery adds 12 new quasars at ‘redshift’ – a measure of distance and speed that determines how light moves through our expanding universe – at or above 7, which corresponds to the first 770 million years of the universe.
The two oldest of the batch, EUCL J172902.75+641018.1 and EUCL J125308.55+705432.3, have redshifts of 7.77 and 7.69, respectively, setting a new record for the oldest quasars ever found. Both are a little more than 13 billion light years apart, and emerged during the first 670 million years of the universe.
“This discovery doubles the number of quasars that we know of that are this ancient,” says Antonio La Marca, ESA Research Fellow in the Euclid team. It took astronomers more than a decade to discover the first 10 or more quasars at redshifts of 7 or greater – but Euclid has already discovered more than that in a year.
“The Euclid team has, for the first time, conducted a true ‘census’ of quasars at the beginning of the universe,” Antonio says. “This is a major step toward understanding these fascinating objects at a more fundamental level.”
Locations of 31 new Euclid quasars
A milestone in cosmic history
The second oldest quasar, found by Deming and colleagues, was recently studied in more detail by Silvia Belladitta and colleagues. These observations revealed that the quasar is embedded in a dusty, gas-filled galaxy that is rapidly forming new stars, pointing to what the host galaxy of an early supermassive black hole might be like.
Quasars are reminiscent of a fascinating period in cosmic history known as the ‘Epoch of Reionization’: when everything shifted from cold and dark (the ‘Dark Ages’) to hot and ‘ionized’ (split by energetic light). This transitional era was an important era that set the stage for much of what we see today.
“Ancient quasars are rare discoveries. They are interesting in their own right, but are also time machines that enable us to explore the early universe and understand how the first generations of galaxies formed,” says ESA Euclid project scientist Valeria Petorino.
“Euclid’s capabilities are unmatched. The telescope combines a large field of view, depth, sharp imaging and unique space-based infrared vision in a way that allows us to pick out rare, extremely distant objects much more efficiently than before.
And it’s not just telescopes: the data processing is only possible because of the thousands of scientists and engineers at the Euclid Consortium, who are working together to make scientific discoveries, combing through vast datasets to identify rare, distant quasars that we can study further using telescopes on the ground.
The 31 quasars reported here were discovered in data from the Euclid Wide Survey, which when completed will cover more than a third of the total sky. Euclid will reveal the secrets of the dark universe; The telescope is exploring its composition, history, evolution, and mapping its large-scale structure, observing billions of galaxies – and revealing many quasars – as it does so.
Euclid discovered the oldest quasar in the universe
Notes to editors
Euclid: 6.6 by D. Yang et al astronomy and astrophysics. DOI: 10.1051/0004-6361/202658883
The highest-redshift quasar in this work is named EUCL J172902.75+641018.1 (redshift of 7.77), and the second highest is named EUCL J125308.55+705432.3 (redshift of 7.69). The previous record-holder, discovered in 2021, has a redshift of 7.64.
about euclid
Euclid launches in July 2023 and begins its regular science observations on 14 February 2024. In November 2023 and May 2024, the world got its first glimpse of the quality of Euclid’s images, and in October 2024 the first piece of his great map of the universe was released. Euclid’s first batch of survey data, including a preview of its deeper regions, was released in March 2025. For more discoveries and data releases from the mission, visit: esa.int/Science_Exploration/Space_Science/Euclid
Euclid is a European mission, built and operated by ESA with contributions from its Member States and NASA. The Euclid Consortium – consisting of more than 2000 scientists from 300 institutions in 15 European countries, the United States, Canada and Japan – is responsible for providing the scientific tools and scientific data analysis. ESA selected Thales Alenia Space as the main contractor to build the satellite and its service module, with Airbus Defense & Space selected to develop the payload module, including the telescope. NASA provided the detectors of the Near-Infrared Spectrometer and Photometer, NISP. Euclid is a medium-range mission in ESA’s Cosmic Vision plan.
Contact
ESA media relations
media@esa.int
